The Infrared Spectrum of Protonated C₇₀

Abstract With the detection of C 60 , 70 and in interstellar medium, fullerenes are currently largest molecules identified space. The relatively high proton affinities support hypothesis that protonated may also be abundant matter. Here, we present first experimental vibrational spectrum H + recorded gas phase. attachment a to causes drastic symmetry lowering, which results rich spectrum. As compared where all C-atoms equivalent due icosahedral symmetry, belongs D 5 h point group has five nonequivalent C-atoms, available as protonation sites. Combined analysis spectra computed at density functional theory level enables us evaluate isomers being formed. We compare IR emission from planetary nebulae, suggests mixture these fullerene analogs could contribute their emission.